JP2004021471A - Fingerprint collating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a fingerprint collating device capable of reliably detecting that fingers are placed on a fingerprint sensor, and performing a correct operation by discriminating when the fingers are placed and when not placed. <P>SOLUTION: The device is provided with a cover 20 that is arranged so as to cover the fingerprint sensor 1 for detecting the fingerprints, and a detection means for detecting the opened/closed state of the cover (a reed switch 25). Further, the device performs a specified operation different from the operation of normal fingerprint collation on the basis of an opened/closed state detection signal of the cover obtained by the detection means. For example, a power supply circuit for feeding a power supply to an internal circuit is switched to a power saving mode. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fingerprint matching device that includes a fingerprint sensor and performs a fingerprint matching operation.
[0002]
[Prior art]
As shown in FIG. 4, the conventional fingerprint matching device uses a finger placement determination circuit 4 and timers 6 and 7 to provide a calibration circuit 8 and a background image acquisition circuit 9 at regular intervals when the finger is not placed. Had started. Further, the power supply circuit 12 always supplies power at full power when the power switch 13 is turned on.
[0003]
That is, the image detected by the fingerprint sensor 1 is captured in the temporary frame 3 by the image capturing circuit 2, and the finger placement signal output from the finger placement determination circuit 4 based on the input image from the temporary frame 3 is a fingerprint signal. If no finger is placed on the sensor 1, the signal is low, and the no-finger-placement signal output via the inverter 5 is high. The first timer 6 and the second timer 7 are activated on the basis of the no-finger-placement signal, and the calibration circuit 8 is activated for the set time on the basis of the activation signal of the first timer 6, and the temporary frame 3 is activated. The sensitivity variation of each cell of the fingerprint sensor 1 is determined based on the density of the image of the fingerprint sensor 1, and the sensitivity adjustment signal is output to the fingerprint sensor 1 so as to correct the sensitivity of each cell of the fingerprint sensor 1 and obtain an even image. At the same time, the second timer 7 is activated, and the background image acquisition circuit 9 is activated for the set time based on the activation signal of the second timer 7, and the image of the temporary frame 3 is used as the background image and the background image frame 10 Transfer to
[0004]
When a finger is placed on the fingerprint sensor 1, a fingerprint image detected by the fingerprint sensor 1 is captured by the image capturing circuit 2 into the temporary frame 3. The finger placement detection circuit 4 detects that the finger has been placed based on the difference between the image of the temporary frame 3 and the image of the background image frame 10, and outputs a detection signal to the fingerprint matching circuit 11. The fingerprint matching circuit 11 processes the image of the temporary frame 3, generates feature data, and matches the fingerprint data with fingerprint data registered in advance to output a matching determination signal. When the power switch 13 is turned on, the power supply circuit 12 always supplies power to each circuit shown in FIG. 4 in a state of full power.
[0005]
[Problems to be solved by the invention]
By the way, in the above-mentioned conventional fingerprint collation device, the state in which the finger is not placed on the fingerprint sensor 1 depends on the set time of the timers 6 and 7, and if the user places the finger in the meantime, the state becomes invalid. Calibration takes place, the captured image is significantly disturbed, and fingerprint matching cannot be performed correctly. Similarly, an image in a finger placement state is captured as a background image, and the finger placement determination cannot be performed. Further, even when not in use, it is necessary to supply all the power, resulting in heat generation and shortening the life of the device.
[0006]
The present invention has been made in view of the above points, and it is possible to reliably detect that a finger is placed on a fingerprint sensor and to perform a correct operation by determining when a finger is placed and when it is not placed. It is an object of the present invention to obtain a fingerprint collation device capable of performing the above.
[0007]
[Means for Solving the Problems]
A fingerprint matching device according to the present invention includes a lid provided so as to cover a fingerprint sensor for detecting a fingerprint, and detection means for detecting the open / closed state of the lid. Based on this, a specific operation different from the normal fingerprint collation operation is performed.
[0008]
Further, a power supply circuit for supplying power to the internal circuit is switched to a power saving mode based on a lid closed state detection signal by the detection means.
[0009]
In addition, a calibration circuit that corrects the sensitivity of each cell of the fingerprint sensor based on a lid closed state detection signal from the detection unit is operated.
[0010]
Further, a background image acquisition circuit for acquiring a background image for finger placement determination is operated based on a lid closed state detection signal from the detection means.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a cross-sectional view of a lid for explaining a fingerprint matching device according to the present invention. As shown in FIG. 1, the lid 20 is attached so as to completely cover the finger rest 21, is fitted with the finger rest 21, the base 22 containing the fingerprint sensor 1 and the hinge 23, and has a structure that can be opened and closed. ing. The magnet 24 mounted on the lid 20 and the reed switch 25 mounted on the base 22 are at opposing positions. The reed switch 25 is turned on when the lid 20 is closed, and turned off when the lid 20 is opened. The open / closed state of the lid 20 is detected. For this reason, when the lid 20 is closed, a finger can never be placed on the finger rest 21 of the fingerprint sensor 1. Each embodiment of the present invention has a lid having the configuration shown in FIG.
[0012]
Embodiment 1 FIG.
FIG. 2 is a block diagram showing a configuration of the fingerprint matching device according to the first embodiment of the present invention. 2, the same parts as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted. In the apparatus shown in FIG. 2, when the lid 20 shown in FIG. 1 is closed and the reed switch 25 is turned on, the power supply circuit 12 enters the power saving state based on the power saving switching signal from the reed switch 25, and the finger placement determination circuit 4. The common circuit power supply such as the fingerprint collation circuit 11 is turned off, and power is supplied only to the other power saving circuits. Other configurations operate similarly to the conventional example.
[0013]
Therefore, according to the first embodiment, it is possible to reliably recognize the state where the finger is not placed, so that the specific control function of the sensor or the like can be reliably operated. Power saving effect can be achieved.
[0014]
Embodiment 2 FIG.
FIG. 3 is a block diagram showing a configuration of a fingerprint matching device according to Embodiment 2 of the present invention. 3, the same components as those of the conventional example shown in FIG. 4 are denoted by the same reference numerals, and description thereof will be omitted. In the apparatus shown in FIG. 3, new reference numerals 14 and 15 denote third and fourth switches that are activated based on an ON signal from a reed switch 25 when the lid 20 is closed. The carburetion circuit 8 is activated on the basis of the activation signal from the switch 14, and the background image acquisition circuit 9 is activated on the basis of the activation signal from the fourth switch 15.
[0015]
Next, the operation of the device shown in FIG. 3 will be described. When the lid 20 shown in FIG. 1 is closed and the finger is not securely placed, the image detected by the fingerprint sensor 1 is taken into the temporary frame 3 via the image taking circuit 2. When the lid 20 is closed and the reed switch 25 is turned on, the third timer 14 is started, and the calibration circuit 8 is started at a predetermined interval. When the calibration circuit 8 is started, the circuit determines the sensitivity variation of each cell of the fingerprint sensor 1 from the density of the image of the temporary frame 3 and corrects the sensitivity of each cell of the fingerprint sensor 1 to obtain a uniform image. To be adjusted.
[0016]
When the lid 20 is closed and the reed switch 25 is turned on, the fourth timer 15 is started at the same time, and the background image acquisition circuit 9 is started at a predetermined interval. When the background image acquisition circuit 9 starts, the circuit transfers the image of the temporary frame 3 to the background image frame as a background image.
[0017]
When the user opens the lid 20, the reed switch 25 is turned off, the third timer 14 is immediately reset, and the operation of the calibration circuit 8 is interrupted. At the same time, the fourth timer 15 is also immediately reset, and the operation of the background image acquisition circuit 9 is interrupted.
[0018]
When the user puts a finger on the fingerprint sensor 1, the fingerprint image detected by the fingerprint sensor 1 is taken into the temporary frame 3 via the image taking circuit 2. The finger placement determination circuit 4 detects that the finger has been placed based on the difference between the image of the temporary frame 3 and the image of the background image frame 10, and outputs a detection signal to the fingerprint matching circuit 11. The fingerprint matching circuit 11 processes the image of the temporary frame 3, generates feature data, and matches the fingerprint data with fingerprint data registered in advance to output a matching determination signal.
[0019]
Therefore, according to the second embodiment, since it is possible to reliably recognize that the finger is not placed, it is possible to prevent the calibration function from being operated accidentally in the finger placed state, and to prevent unauthorized operation in the finger placed state. It is possible to prevent a background image from being captured.
[0020]
【The invention's effect】
As described above, according to the present invention, by detecting that the lid is in the closed state, it is possible to reliably recognize the state where the finger is not placed, so that the specific control function of the sensor can be reliably operated. It is possible to determine when the finger is placed and when it is not placed and perform a correct operation.
[0021]
In addition, since it is possible to recognize that the lid is in the closed state, that is, in the unused state, the power saving state can be reliably set without giving the user a sense of incongruity.
[0022]
Also, in the past, the dark blue carburetion function was implemented by removing the moment when the finger would not be placed, but since the lid is closed, that is, the finger is not placed reliably, It is possible to prevent the calibration function from being operated accidentally in the state.
[0023]
Furthermore, since it is possible to reliably recognize that the lid is closed, that is, that the finger is not placed, it is possible to prevent an illegal background image from being taken in the state where the finger is placed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a lid for explaining a fingerprint matching device according to the present invention.
FIG. 2 is a block diagram showing a configuration of the fingerprint matching device according to the first embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a fingerprint matching device according to Embodiment 2 of the present invention.
FIG. 4 is a block diagram showing a configuration of a fingerprint matching device according to a conventional example.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 fingerprint sensor, 2 image capture circuit, 3 temporary frame, 4 finger placement determination circuit, 5 inverter, 6 first timer, 7 second timer, 8 calibration circuit, 9 background image acquisition circuit, 10 background image frame 11 fingerprint matching circuit, 12 power supply circuit, 13 power switch, 14 third timer, 15 fourth timer, 20 lid, 21 finger rest, 22 base, 23 hinge, 24 magnet, 25 reed switch.

Claims (4)

A lid provided to cover a fingerprint sensor for detecting a fingerprint,
Detecting means for detecting the open / closed state of the lid,
A fingerprint matching device, wherein a specific operation different from a normal fingerprint matching operation is performed based on a lid closed state detection signal by the detection means. The fingerprint matching device according to claim 1,
A fingerprint matching device, wherein a power supply circuit for supplying power to an internal circuit is switched to a power saving mode based on a lid closed state detection signal from the detection unit. The fingerprint matching device according to claim 1,
A fingerprint matching device, comprising: operating a calibration circuit that corrects the sensitivity of each cell of the fingerprint sensor based on a lid closed state detection signal from the detection unit. The fingerprint matching device according to claim 1,
A fingerprint matching device, comprising: operating a background image acquisition circuit that acquires a background image for finger placement determination based on a lid closed state detection signal from the detection unit.

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